Added: Aug 25, 2017 12:28 pm
PART 1: GENERAL
1. SCOPE OF WORK
Work under this contract consists of construction of an access ramp and improvements to the Leech Lake embankment located immediately north of the Leech Lake Dam. Work shall include, but not be limited to, clearing and grubbing the east embankment slope and adjacent area to the limits of the vegetative free zone; seeding and mulching areas disturbed by clearing and grubbing that are not covered with other materials; stripping topsoil on east and west slopes and regrading stripped slopes to provide a uniform slopes free of ruts and high spots, placing stripped topsoil back on regraded slopes, and seeding and mulching the finished regraded slopes; removal of existing riprap on the east embankment slope adjacent to the Leech River and placement of the riprap in a stockpile on the prepared ground surface with a geotextile base at the location identified in the plans; placing granular fill, topsoil, seed, and mulch on the existing exposed riprap surface on the west side of the embankment centerline; stripping topsoil on the footprints of the new ramp, riprap, and drainage aggregate on the eastern slope of the embankment and adjacent ground; installing drainage aggregate on the east embankment slope on the north side of the access ramp; placing drainage aggregate, geotextile, and 18?inch reinforced concrete pipe (RCP) beneath the footprint of the ramp in the area of the toe of the slope; placing granular fill for the access ramp; placing geotextile overlain by bedding and riprap on the embankment between the river and the ramp and on portions of the southern slope of the ramp; placing topsoil, seed, and mulch on the finished surface of the ramp not covered with riprap; and restoring any areas disturbed by the Contractor's actions to pre?project conditions.
2. WORK RESTRICTIONS
Work Hours shall be limited to the hours of 7:00 AM to 5:30 PM Monday through Friday, excluding Federal holidays, unless prior approval is provided by the Contracting Officer. Contractor operations shall not interfere with normal operations of the site.
The Contractor shall be responsible for completing all operations associated with construction of project features in compliance with the current publication of U. S. Army Corps of Engineers EM 385?1?1 Safety and Health Requirements Manual as well as all applicable OSHA regulations and Minnesota State codes governing work environment safety. The Contractor shall maintain a safe work environment during all phases of the work and ensure that all workers are properly trained in safe work techniques, are aware of hazards in the activities performed, and are provided with the necessary training and equipment, in good working order, to perform the work without accident or injury.
4. MEASUREMENT AND PAYMENT
The payment provided for in the contract shall constitute full compensation for furnishing all materials and for performing all work under the contract in a complete and acceptable manner. The contract work shall include providing plant, equipment, tools, supplies, labor, supervision, incidental materials, quality control, environmental protection, performance and payment bonding, meeting safety requirements, and for performing all work required for which separate payment is not otherwise provided. Compensation for all work shown, specified, or essential to completion of the project (whether or not the specific material or operation is indicated) shall be included in the bid price. The payment provided for in the contract includes compensation for all risk, loss, damage, and expense arising out of the nature of the work or its prosecution, subject to conditions of the contract. Payment for each contract line item will constitute full compensation for furnishing the materials and constructing the work complete in place as specified.
b. Base Contract: Access Ramp and Embankment Improvements
Payment will be made on a job basis complete for the construction of the access ramp and embankment improvements as shown and specified, exclusive of the embankment slope regrading identified on plan sheet CD101. All incidentals required to complete the work shall be included in the bid price.
c. Option 1: Embankment Slopes Regrading
Payment will be made on a job basis complete for completing the embankment slope regrading as shown and specified. Specific tasks include stripping of topsoil, regrading of embankment slopes, placement of stripped topsoil back on the regraded slopes, and seeding and mulching. All incidentals required to complete the work shall be included in the bid price.
a. Minnesota Department of Transportation (MNDOT): All references to the Minnesota Department of Transportation relate to the requirements in the 2016 edition of Standard Specifications for Construction.
b. ASTM C76 Standard Specification for Reinforced Concrete Culvert, Storm Drain, and Sewer Pipe, 2016 publication.
c. ASTM C136/C136M Standard Test Method for Sieve Analysis of Fine and Coarse Aggregates, 2014 publication.
d. ASTM D6825 Standard Guide for Placement of Riprap Revetments, 2014 publication.
Contractor surveys are required to verify that materials are placed to the thickness and geometry required by the contract documents. The Contractor shall make surveys as the work progresses to verify lines, grades and thicknesses established for completed work. The surveys shall be conducted in the presence of an authorized representative of the Contracting Officer, unless this requirement is waived by the Contracting Officer. Following placement of bedding, riprap, drainage aggregate, and granular fill the required cross sections shall be provided to the Contracting Officer. Review and approval of the surveyed cross sections shall not constitute final acceptance of the work.
a. Surveyor Qualifications: All survey data collection shall be accomplished under the direction of a licensed and registered professional surveyor. The licensed and registered professional surveyor shall be on site at all times during surveying activities.
b. Geospatial Data:
i. Metadata: All geospatial information submitted must include Federal Geographic Data Committee (FGDC) compliant metadata. See U. S. Army Corps of Engineers publication EM 1110?1?2909, Engineering and Design: Geospatial Data and Systems (2012) or http://www.fgdc.gov/metadata/documents/workbook_0501_bmk.pdf for more information.
ii. Geospatial Information: Geospatial data that may be used include any of the following information: GIS drawings/maps, topographic mapping, georeferenced digital drawings generated from hard copy maps/drawings, high?order geodetic control (horizontal and vertical) surveys using Global Navigation Satellite System (GNSS) or Global Positioning System (GPS) and conventional survey techniques for control and property/boundary surveys. For recommended accuracies and tolerances see EM 1110?1?1005 Chapter 6 and EM 1110?1?1003 Chapter 8.
iii. GNSS/GPS Data: The Contractor shall collect and submit to the Contracting Officer the GNSS observables (L1/L2) in both the GNSS receiver's native format and the Receiver Independent Exchange Format (RINEX) all Real Time Kinematic, Static, and Differential Surveys. If a Virtual Reference Network (VRS) is not used, a completed observation log sheet is required for each base station occupation/session. All GNSS/GPS control surveys require "closed" observation campaigns. A "closed" campaign consists of more than one observation of each control point. Use appropriate observation times for the level of accuracy required for the type of work.
iv. Field Notes/Books: The Contractor shall submit all original field books/notes/computation sheets fully describing the geospatial data collection and all significant events related to said event. This allows the Contracting Officer to apply quality assurance measures to the data collect. Compile the format and content of field notes/books according to U. S. Army Corps of Engineers publication EM 1110?1?1005, Engineering and Design: Control and Topographic Surveying (2007) ?Chapter 12.
v. Datums and Units of Measure: Use the spatial reference information on the drawings. Ensure all geospatial data submitted is referenced to the National Spatial Reference System (NSRS).
c. Geospatial Data Collection Equipment: Positioning equipment for geospatial data collection shall be capable of achieving the required accuracy for the work being performed. Perform initial calibration and subsequent checks in accordance with the manufacturer's instructions. Provide documentation of all calibrations and subsequent checks to the Contracting Officer. Positioning equipment includes, but is not limited to, the following: conventional/robotic total stations, GNSS/GPS systems, digital levels and hydrographic survey equipment.
d. Geospatial Data Collection: The Contracting Officer reserves the right to be present for all geospatial data collection field work. For preliminary, as?built, and quantity surveys and verification of design section surveys perform a breakline and grid style survey/point cloud of the project area at sufficient spacing to accurately define site conditions and as?built conditions but not to exceed 25 feet. Conduct the breakline and grid style survey/point cloud with an equipment type that can meet or exceed the requisite accuracies. Produce and submit the following for approval: (1) a DTM surface file in Bentley InRoads .DTM format, LandXML format, or in a format compatible with Bentley InRoads approved by the Contracting Officer. The surface file shall include triangles, breaklines and surface boundary features. (2) A vector file of planimetric features and point data in a format compatible with Bentley MicroStation. Draw all point and vector (non?raster) data at elevation. (3) XYZ text file with descriptions. (4) Metadata (in an .xml, .gen, or .met file format) associated with submittal.
e. Preliminary Surveys: The Contractor shall run a preliminary survey, locating the control line, all other significant features that may affect the design and/or construction of the project within the limits of the work, and all existing conditions from which construction of the design features will be based. Submit all geospatial data (raw and processed) used to derive preliminary survey documentation as evidence of performance and for review by the Contracting Officer for compliance with applicable standards and guidance. At a minimum, collect the preliminary survey using the appropriate data collection equipment (paragraph Geospatial Data Collection Equipment) for the accuracy level required. Deliver all geospatial data according to paragraph Geospatial Data.
f. As?Built Surveys: After construction, the Contractor shall conduct an as?built survey of all project elements and features to accurately document the relationship between the design location and construction location. Provide all geospatial data (raw and processed) used to derive as?built documentation to the Contracting Officer. Ensure data is in compliance with applicable standards and guidance. At a minimum, electronically collect all as?built surveys of project elements and features using the appropriate data collection equipment (paragraph Geospatial Data Collection Equipment) for the accuracy level required and produce sufficient documentation of the as?built conditions. Deliver all geospatial data according to paragraph Geospatial Data. Perform the surveys using appropriate methods for the verification of the thickness and geometry of the materials placed as required by the contract documents.
a. Granular Fill: Granular fill shall meet the requirements for Sand Cover as defined in MNDOT 3149.2K.
b. Drainage Aggregate: Drainage aggregate shall meet the requirements for Medium Filter Aggregate as specified in MNDOT 3149.2.J.1.
c. Geotextile: Geotextile encasing the drainage aggregate shall meet the requirements as specified in MNDOT 3733 for Type 1 geotextile. The geotextile placed as a base for the riprap/bedding scour protection section as well as a base for the riprap stockpile obtained from excavation of existing riprap shall meet the requirements as specified in MNDOT 3733 for Type IV geotextile. The geotextile supplied shall be a needle punched non?woven material.
d. Reinforced Concrete Pipe: Reinforced concrete pipe shall meet the requirements for the size and class of pipe as shown in the plans and as specified in ASTM C76.
e. Riprap and Bedding: Riprap and bedding shall be obtained from a source listed in the approved materials listing or from a source chosen by the Contractor and approved by the Contracting Officer. Riprap and bedding shall meet the gradation requirements shown in the attachments to this scope of work. Riprap and bedding shall be of a suitable quality to ensure permanence in the project and in the climate in which it is to be used. It shall be free from cracks, bedding, seams and other defects that would tend to increase its deterioration from natural causes. A crack is considered to be detrimental if it is more than 4 mil wide and is continuous for one?third the dimension of at least two sides of the stone. The stone shall be clean and reasonably free from soil, fines, and shall contain no refuse. Any foreign material adhering to or combined with the stone as a result of stockpiling shall be removed prior to placement. The maximum aspect ratio (greatest dimension?:?least dimension) of any piece of stone for size ranges shall be not greater than 3:1 when measured across mutually perpendicular axis.
f. Topsoil: Topsoil obtained from stripping operations will be reused in the project to the extent possible. Imported topsoil shall be screened lawn and garden grade black topsoil free of roots, weeds, rock, and other debris.
g. Seed: Seed will meet the requirements of MNDOT3876 table 3876?1 for mix number 25?142 Agricultural Roadside.
h. Mulch: Mulch shall be composed of straw or paper fiber. Straw mulch materials shall consist of wheat, oat, or rye straw, hay, grass, or other plants approved by the Contracting Officer. Mulch materials shall be native to the region. The mulch material shall be air dry, reasonably light in color, and shall not be musty, moldy, caked, or otherwise of low quality. The mulch shall be seed free or fumigated to prevent introduction of weeds. The use of mulch that contains noxious weeds will not be accepted. Dry mulching material which breaks and does not bend is unacceptable. Mulch shall have a consistency for placing with commercial hydroseeding or mulch blowing equipment. Paper fiber mulch shall be recycled newsprint that is shredded for the purpose of mulching seed.
The Contractor shall be required to submit for approval the following submittals. Approval by the Government of all the listed submittals except the as?built drawings will be required before work on site can be initiated.
a. Safety Plan: The Contractor shall submit a safety plan for performing the work in conformance with the Safety and Health Requirements Manual, US Army Corps of Engineers EM 385?1?1. The safety plan shall be reviewed by the Corps and discussed at a pre?construction meeting.
b. Surveyor Qualifications: The Contractor shall provide documentation verifying that the individual responsible for completing survey requirements is a licensed and registered professional surveyor in the State of Minnesota.
c. Geospatial Data: The Contractor shall provide all geospatial data and other survey related information as specified in the SURVEYS section.
d. Erosion Protection Plan: The Contractor shall not require a National Pollutant Discharge Elimination System (NPDES) Permit from the State of Minnesota. The total construction area is below the minimum one acre requirement. The Contractor shall, however, take appropriate steps to minimize erosion from the site into adjacent undisturbed areas. Steps include, but are not limited to, installation of a silt curtain, silt fence, or some other satisfactory type of barrier around the perimeter of disturbed areas.
e. Disposal Facilities: The Contractor shall designate in writing any disposal facilities that are to receive disposal material from this project. The facilities shall be permitted by the Minnesota Pollution Control Agency to receive the materials being placed there.
f. Granular Fill: The Contractor shall provide sieve analysis documentation, as specified in ASTM C136/C136M, from the material supplier showing that material available at the source meets requirements as specified. Documentation from prior completed testing is acceptable. A jar sample of the material to be furnished shall be provided to the Contracting Officer prior to delivery of materials to be placed in the project.
g. Drainage Aggregate: The Contractor shall provide sieve analysis documentation, as specified in ASTM C136/C136M, from the material supplier showing that material available at the source meets requirements as specified. Documentation from prior completed testing is acceptable. A minimum 12 lb. sample of the material to be furnished shall be provided to the Contracting Officer prior to delivery of materials in the project.
h. Reinforced Concrete Pipe (RCP): The Contractor shall provide certification from the pipe supplier that the pipe and flared end sections meet requirements as shown and specified in this scope of work.
i. Geotextile: The Contractor shall provide manufacture's technical specifications from the supplier of the two types of geotextiles required for this project verifying that the materials meet specification requirements.
j. Riprap Material Source and Gradation: The Contractor shall designate the material source for riprap not less than one week prior to delivery and provide documentation verifying that the riprap meets gradation requirements using one of the methods outlined in the attachments at the end of this scope of work. Unless waived, the Contracting Officer or his representative will be present during the gradation testing to confirm that the riprap meets the specified gradation requirements. All costs associated with gradation testing, including any failed tests, shall be incidental to the bid price.
k. Bedding: The Contractor shall provide documentation for the material source for bedding as well as gradation test results verifying that gradation requirements are met. Unless waived, the Contracting Officer or his representative will be present during the gradation testing to confirm that the bedding meets the specified gradation requirements. The costs for gradation testing, including any failed tests, shall be incidental to the bid price.
l. Seed: The Contractor shall provide documentation from the seed supplier verifying that the seed meets the specification requirements and is from the latest year's seed crop.
m. Survey Data and Marked?Up Contract Drawings: Within 30 days after construction is complete, the Contractor shall submit all survey data required by this scope?of?work as well as Contractor marked up drawings reflecting any changes made to the contract design. Approval and acceptance of the survey data and marked up drawings is required before final payment will be made to the Contractor.
9. MINNESOTA ONE CALL EXCAVATION NOTICE SYSTEM
The Contractor shall meet the requirements of Minnesota Statutes, Chapter 216D "One Call Excavation Notice System." The Gopher State One Call notification center telephone number for outstate is (800) 252?1166. Work shall not begin onsite until utilities have been located and marked.
10. PRECONSTRUCTION MEETING AND COORDINATION
Prior to initiation of construction, the Contractor shall meet with the Contracting Officer's Representative at the project site to discuss the Contractor's plan of operation, the Contractor's safety plan, and any issues that the Government or the Contractor may have.
11. STAGING AREA
The Contractor shall use a staging area within the work limits.
a. Shaping Slope where Pedestrian Bridge was Removed: A pedestrian bridge previously removed from the area where drainage aggregate is to be placed resulted in ground surface irregularities. The Contractor shall grade these surface irregularities smooth to match the adjacent ground surface.
b. Clearing and Grubbing: The Contractor shall clear and grub vegetation in areas as shown on the contract drawings. Clearing shall consist of the felling, trimming, and cutting of trees and other vegetation designated for removal. Grubbing shall consist of the removal stumps, roots larger than 3 inches in diameter, and matted roots from the designated grubbing areas. All clearing and grubbing material shall be properly disposed of offsite at facility approved to receive such material. Holes and depressions resulting from clearing and grubbing shall be filled with material similar to the adjacent soils or, if similar material is not available, with topsoil in lifts with a maximum thickness of 12 inches and compacted with a minimum of three passes of standard compaction equipment.
c. Stripping: The Contractor shall strip topsoil within the limits shown or indicated. Topsoil shall be stripped to the extent that all organic material has been removed from areas where granular fill, riprap and bedding, and drainage aggregate are to be placed or where the embankment side slopes are to be regraded. Topsoil shall be kept separate from other excavated materials, brush, litter, objectionable weeds, roots, stones larger than 1?inch in diameter, and other materials that would interfere with planting and maintenance operations. Topsoil shall be spread on areas already graded and prepared for topsoil, or transported and deposited in stockpiles convenient to areas that are to receive application of the topsoil later, or placed at locations indicated or specified. Any surplus topsoil shall be spread on site within the work limits.
d. Regrading Embankment Slopes: The Contractor shall regrade the embankment side slopes to the limits shown or indicated. Once topsoil has been stripped, the Contractor shall regrade the existing embankment side slopes to a smooth uniform finish by filling in ruts and depressions and removing high spots. The Contractor shall topsoil, seed and mulch the finished regraded surface in accordance with this scope of work.
e. Riprap Excavation: The Contractor shall excavate the existing riprap to the limits shown on the contract drawings. The Contractor shall provide at least 3 working days' (Monday - Friday) notice prior to stripping existing riprap to arrange for a Government inspector to be onsite during this work to verify and document the soil characteristics underlying the riprap and riprap washing operations. The riprap removal shall be completed in one continuous operation without remobilization or delays. Pervious sand soils shall be prevented from contamination or erosion until covered with the ramp or drainage aggregate surfacing. Any contaminated existing filter material under the drainage aggregate material shall be removed and replaced with suitable material before placement of geotextile. The excavated riprap shall be stockpiled at the location shown in the attachments to this scope?of?work. The Contractor shall coordinate the exact location and limits of the stockpile with Park Ranger Timm Rennecke at 651?290?5470. Placement of the stockpile shall not impact the access to the clearing to the west of the stockpile site. Prior to stockpiling, the riprap shall be washed to remove any soil that is intermixed with it and the stockpile site prepared to receive the riprap. The stockpile site shall be stripped of vegetation and shaped to create a smooth uniform surface. This prepared surface shall then be covered with geotextile of sufficient areal extent that it will extend outside the limits of the stockpile by at least one foot in all directions. The geotextile shall be in intimate contact with the prepared ground surface and be free of folds and tension. Riprap shall be placed at the stockpile location in such a manner and from a drop height so as to not damage the underlying geotextile. Construction equipment placing the riprap shall not operate directly on the riprap or geotextile.
f. Granular Fill Placement over Riprap (Drawing C?101 Keynote 1): The Contractor shall place granular fill over the existing riprap on the west side of the embankment centerline such that placement of granular fill does not displace riprap. Granular fill shall be placed to fill voids in the riprap and to create a smooth uniform surface on which topsoil is to be placed.
g. Drainage Aggregate Placement: The Contractor shall place drainage aggregate to the lines and grades shown on the contract drawings along the lower embankment slope north of the ramp as well as within the footprint of the ramp. For the portion of drainage aggregate within the footprint of the ramp, geotextile shall be placed as a base prior to placement of the drainage aggregate. The geotextile fabric shall wrap all of the drainage aggregate material within the ramp structure except where the drainage aggregate daylights at the north and south ends. The ground surface on which the geotextile is to be placed shall be prepared so that it is smooth and free of irregularities that could damage the geotextile or cause it to not be in constant contact with the ground surface. After preparation of the ground surface, the geotextile shall be placed to the limits shown with the geotextile in direct contact with the ground surface and free of tensile stresses, folds, and wrinkles. If seams are required, they shall be overlaid a minimum of 24 inches with upslope sections overlapping downslope sections. The drainage aggregate within the footprint of the ramp shall be placed along with the reinforced concrete pipe and associated flared end sections. Prior to placement of the pipe, the drainage aggregate base shall be compacted sufficiently so that there is no movement of the pipe after it is placed. The drainage aggregate shall be brought up around the pipe as shown. Placement of the drainage aggregate shall employ methods that do not displace the pipe. Once the pipe and drainage aggregate have been placed as shown, the finished surface shall be covered with geotextile so that it is in continuous contact with the underlying drainage aggregate and upper portion of the pipe.
h. Granular Fill Placement for Access Ramp: Once the drainage aggregate system has been placed as shown and specified, the Contractor shall place granular fill on the ramp to the dimensions shown. Granular fill shall be placed using methods that do not displace the geotextile, pipe, or drainage aggregate. Material shall be placed in lifts not exceeding 6 inches for the first 12 inches above the drainage system, spread with low ground pressure equipment, and compacted with manually operated equipment specifically designed for compaction. Compaction shall be achieved with a minimum of three passes of the compaction equipment over each lift. For lifts in excess of 12 inches above the drainage system or for portions of the ramp that are not above the drainage system, granular fill shall be placed in lifts with a maximum thickness of 12 inches and compacted with a minimum of three passes of standard compaction equipment.
i. Placement of Scour Protection Section: The Contractor shall place riprap, bedding, and geotextile in accordance with recommended practice in ASTM D6825. The scour protection section for the ramp consists of geotextile overlain by bedding which is in turn overlain by riprap. Prior to placement of geotextile, the ground surface shall be prepared as detailed in the paragraph: Drainage Aggregate Placement so that there is a smooth uniform surface on which to place the geotextile. Geotextile shall be placed so that it is in continuous contact with the underlying ground surface and shall be free of tensile stresses, folds, and wrinkles. Once the geotextile is placed, bedding material shall be spread uniformly on the geotextile surface to the lines and grades indicated and in such manner as to avoid disturbance to the geotextile and subgrade. Placing by methods which tend to segregate the particle sizes or cause mixing of the separate layers will not be permitted. Placement shall begin at the bottom of the area to be covered and continue up slope. Subsequent loads of material shall be placed against previously placed material in such a manner as to ensure a relatively homogenous mass. Any damage to the surface of the prepared base during placing of the material shall be repaired before proceeding with the work. Compaction of bedding material will not be required, but the surface shall be finished to present an adequately even surface, free from mounds or windrows. Riprap shall be placed over the bedding surface to the lines and grades indicated. Riprap shall be placed to produce a well graded mass free of pockets of small stone and clusters of larger stones. Riprap shall be placed to its full thickness in one operation and in such a manner that is does not displace underlying bedding material or riprap that has been previously placed. Placement shall start at the bottom of the slope and proceed upslope. Placement by dumping or pushing the material down slope will not be allowed. The finished surface of the slope shall be adjusted as required to result in a smooth uniform surface.
j. Placement of Topsoil: The Contractor shall spread topsoil, whether obtained from stripping operations or imported, on areas ready to receive topsoil with a low ground pressure dozer, skid steer loaders, or other equipment capable of lightly compacting the soil and approved by the Contracting Officer. Topsoil shall be spread in one lift of uniform thickness. The finished grade shall be such that after subsequent treatment (tillage, topsoiling and planting) the planted grade shall be even with adjoining turfed areas. Construction equipment shall be kept of the finished topsoil surface.
k. Seeding: The Contractor shall install the specified seed mix during the period from April 15 through October. Seed shall be applied by hydroseeding methods or another method proposed by the Contractor and approved by the Contracting Officer. Seed shall be applied at a rate not less than 45 pounds per acre. Mulch shall be applied at a rate of 1 ton/acre. During application, the spray shall be directed to obtain a uniform material distribution as evidenced by a formation of a "blotter?like" cover, with about 5% void area. The mulch shall permit percolation of water to the underlying soil. The seed mixed with water shall be applied within 1 hour after adding to the tank.
l. Temporary Seeding: If the Contractor is not able to seed the site with the permanent seed mix by the end of September, a temporary seed mix consisting of 10 pounds of oats or 1?1/2 bushels of winter wheat per acre shall be applied and seeding with the permanent seed mix shall be delayed until the following season's seeding window.
m. Maintenance to Establish Turf: Once the seed has been installed, the Contractor shall perform maintenance (watering) as required until an acceptable stand of turf has been established. An acceptable stand of turf is defined as having a minimum height of 2 inches and have a density of 100 grass plants per square foot and be reasonably free of weeds and visual imperfections as assessed by the Contracting Officer.
16. SITE RESTORATION AND CLEAN?UP
The Contractor shall restore all areas damaged by construction operations to pre?project conditions.